* {
    margin: 0;
    padding: 0;
}
li {
    list-style: none;
}
a {
    text-decoration: none;
}
.w {
    width: 1200px;
    margin: auto; 
}
/* 使用双伪元素清除浮动 */
.clearfix:before,.clearfix:after {
    content: "";
    display: table;
}
.clearfix:after {
    clear: both;
}
.clearfix {
    *zoom:1;
}
body {
    background-color: #f3f5f7;
}
.header {
    height: 42px;
    margin: 30px auto;
}
.logo {
    float: left;
    width: 198px;
    height: 42px;
}
.nav {
    float: left;
    margin-left: 60px;
}
.nav li{
    float: left;
    margin: 0 15px;
}
.nav li a {
    display: block;
    height: 42px;
    padding: 0 10px;
    line-height: 42px;
    font-size: 18px;
    color: #050505;
}
.nav li a:hover {
    border-bottom: 2px solid #00a4ff;
}
.search {
    float: left;
    width: 412px;
    height: 42px;
    margin-left: 50px;
}
.search input {
    float: left;
    width: 345px;
    height: 40px;
    border: 1px solid #00a4ff;
    border-right: 0;
    color: #bfbfbf;
    font-size: 14px;
    padding-left: 15px;
}
.search button {
    float: left;
    width: 50px;
    height: 42px;
    /* 文本框与按钮为行内块元素 中间默认有缝隙 需要手动去除 */
    border: 0;
    background: url(images/fa-search.png);
}
.user {
    float: right;
    margin-right: 30px;
    line-height: 42px;
}
.banner {
    height: 421px;
    background-color: #1c036c;
}
.banner .w {
    height: 421px;
    background: url(images/banner2.png) no-repeat top center;
}
.banner .subnav {
    float: left;
    width: 190px;
    height: 421px;
    background-color: rgb(0,0,0,0.3);
}
.banner .subnav li {
    height: 45px;
    line-height: 45px;
    padding: 0 20px;
}
.banner .subnav li a {
    font-size: 14px;
    color: #ffffff;
}
.banner .subnav li a:hover {
    color: #00a4ff;
}
.banner .subnav li a span {
    float: right;
}
.banner .course {
    float: right;
    width: 230px;
    height: 300px;
    background-color: #ffffff;
    /* 浮动的盒子不会有外边距合并 BFC问题很重要！！！ */
    margin-top: 50px;
}
.course h2 {
    height: 48px;
    text-align: center;
    line-height: 48px;
    font-size: 18px;
    color: #ffffff;
    background-color: #9bceea;
}
.bd {
    padding: 0 20px;
}
.bd ul li {
    padding: 15px 0;
    border-bottom: 1px solid #cccccc;
}
.bd ul li h4 {
    font-size: 16px;
    color: #4e4e4e;
}
.bd ul li p {
    font-size: 12px;
    color: #a5a5a5;
}
.bd .all {
    display: block;
    height: 38px;
    border:1px solid #00a4ff;
    text-align: center;
    line-height: 38px;
    margin-top: 5px;
    background-color: #ffffff;
    font-size: 16px;
    font-weight: 700;
}
.goods {
    width: 1200px;
    height: 60px;
    line-height: 60px;
    background-color: #ffffff;
    box-shadow: 0 2px 3px 3px rgb(0,0,0,0.3);
    margin-top: 10px;
}
.goods h3 {
    float: left;
    margin-left: 30px;
    font-size: 16px;
    color: #00a4ff;
}
.goods ul {
    float: left;
    margin-left: 30px;
}
.goods ul li {
    float: left;
}
.goods ul li a {
    font-size: 16px;
    color: #050505;
    padding: 0 30px;
    border-left: 1px solid #cccccc;
}
.goods .mod {
    float: right;
    margin-right: 30px;
    font-size: 14px;
    color: #00a4ff;
}
.box {
    margin-top: 30px;
}
.box-hd {
    height: 45px;
}
.box-hd h3 {
    float: left;
    font-size: 20px;
    color: #494949;
}
.box-hd a {
    float: right;
    font-size: 12px;
    color: #a5a5a5;
    margin-top: 10px;
    margin-right: 30px;
}
.box .box-hd a:hover {
    color: #00a4ff;
}
.box-bd ul {
    /* 避免撑开盒子使最右边再起一行 */
    width: 1250px;
}
.box-bd ul li {
    position: relative;
    float: left;
    width: 228px;
    height: 270px;
    background-color: #ffffff;
    margin-right: 15px;
    margin-bottom: 15px;
}
.box-bd ul li>img {
    width: 100%;
}
/* 子绝父相 */
.box-bd ul li em {
    position: absolute;
    top: 4px;
    right: -4px;
}
.box-bd ul li h4 {
    margin: 20px 20px 20px 25px;
    font-size: 14px;
    color: #050505;
    font-weight: 400;
}
.box-bd .info {
    margin: 20px 20px 20px 25px;
    font-size: 12px;
    color: #999;
}
.box-bd .info span {
    color: #ff7c2d;
}
.footer {
    margin: auto;
    height: 415px;
    background-color: #ffffff;
}
.footer .tail {
    width: 1200px;
    padding-top: 35px;
    margin: auto;
}
.copyright {
    float: left;
}
.links {
    float: right;
}
.copyright p {
    font-size: 12px;
    color: #666666;
    margin: 20px 0 15px 0;
}
.copyright .app {
    display: block;
    width: 118px;
    height: 33px;
    border: 1px solid #00a4ff;
    font-size: 16px;
    text-align: center;
    line-height: 33px;
    color: #00a4ff;
}
.copyright .app:hover {
    color: blue;
}
.links dl dt {
    font-size: 16px;
    color: #333333;
    margin-bottom: 5px;
}
.links dl dt dd a {
    font-size: 12px;
    color: #333333;
}
.links dl dt dd a:hover {
    color: red;
}
.links dl {
    float: left;
    margin-left: 120px;
}